Thin-film carbon forced warm-air-heating unit

ABSTRACT

A forced warm-air heating apparatus, a forced warm-air heating system, and method to heat warm-air using an enclosure containing a plurality of thin film carbon-based heating elements configured and arranged to heat a desired heating space driven by a fan assembly, is described. The plurality of thin film heating elements is further ured and arranged to deflect and divide air flow as it flows through the heating enclosure.

FIELD OF THE INVENTION

The invention relates generally to the heating of spaces. Moreparticularly, this invention relates to a forced air heating system toheat space using flat carbon-based resistive elements.

BACKGROUND OF THE INVENTION

Energy usage in homes, particularly the heating of homes, substantiallycontributes to the usage of fossil fuels. There is a growing need topromote more sustainable living habits by reducing fossil fuel emissionsusing cleaner forms of energy. Heating energy derived from fossil fuels,such as coal, wood, natural gas, and oil causes atmospheric pollution,and contributes to global warming. Additionally, the supplies of fossilfuels are also becoming increasingly scarce.

Electrical heating provides an alternative to fossil fuels, but lacksthe efficiency to be economical. There are generally two forms ofelectrical heating: vapor-compression based or resistive heating based.Vapor-compression based heating involves circulating a heat transfermedium between a desired heating area and the surrounding environmenthaving a higher heat potential driven by a heat pump. However, when theheat potential in the surrounding environment is low, the efficiency ofvapor-compression is diminished, if not rendered inoperable. Toillustrate this issue further, the coefficient of performance of aheating system (COP) is generally calculated with the following formula:

${C\; O\; P} = \frac{T_{R}}{T_{R} - T_{o}}$

Where T_(R) is the room temperature and T_(O) is the outsidetemperature. In vapor-compression based heating system, the COP isdirectly related the heating potential, e.g. the difference in theoutside temperature and the room temperature. Thus, in mild conditionswhere the room temperature is relatively low and the outside temperaturerelatively high, the COP can be up to 300%. However, once the outsidetemperature falls below a certain level and/or the inside temperaturereaches a sufficiently high value; the COP reduces dramatically below100%. This means that on a cold winter's day, a heat-pump will struggleto heat a house, and once it get the temperature of the house to areasonable level, it will be sufficiently ineffective at keeping thetemperature at that elevated state.

Conventional filament heaters and resistive air-heaters employ a heatingelement that heat up as electric current passed though the heatingelement. Present resistive based heating systems generate heat energy byforcing air over the resistive heating elements that are transferred tothe desired heating spaces. Heating elements are typically electricfilaments and are generally characterized by their high electricalresistance. Electrical filaments are generally constructed of metalalloys, such as Nichrome, Cupronickel, and Kanthal. The filaments areformed as a fine wire, ribbon, or strip. Electric heat elements convertelectric energy into conductive, radiative, and convective heat energy,which have a low efficiency in generating convection heating energy.Convective heat energy is generally the most useful since the energytransfers to the air, which can be transferred to the desired heatingarea in the house, but are also generally the least produced due to thehigh temperature resistance between the heating elements and thetransferred medium. Conductive heat energy is generally the leastuseful, but is the most prevalent in the process. Conductive heat energyis considered wasted heat since it heats the ducting of the heatingsystem, which does not generally contribute to heating the desired areaof the space or house. Radiative heat energy is also essentially wastedenergy since only a small fraction of the radiative energy is transferto the air to be used to heat the desired heating space.

In most heater applications, heat is transferred to air throughconvection and to other surroundings through radiation. Most resistiveheater elements glow bright red or orange when current is applied,indicating a large portion of the electric energy used by the heatergenerates radiation. Where this is an efficient way to heat surroundingobjects that can absorb the radiation, it is not an efficientheat-transfer mechanism for a ducted air-heating system. In a ductedsystem, the object is to heat the air and not the surrounding ductingsince the ducting transfers a good portion of its heat to thesurroundings thus increasing losses. When a filament type heater isused, a good deal of the electric energy that is turned into heat islost to through radiation that merely heats the ducting and not the air.The only useful part of the heat going into the air is transferredthrough convection.

SUMMARY OF THE INVENTION

Various embodiments of the present invention overcome the limitations ofpresent resistive heating elements through the use of thin film heatingelements, such as thin film carbon fibers. Thin film heating elements,such as thin film carbon fibers, have a superior efficiency of heatingair by delivering more heated air to a desired heating space for a givenquantity of electric energy used. Three features of the thin filmheating elements, such as thin film carbon fibers, contribute to theirsuperior efficiency. Firstly, the thin film heating elements do notreach high temperatures and thus do not generate a large quantity ofradiation resulting in more energy available for convection heattransfer to the surrounding air as compared to Nichome, Kanthal, andCupronickel. Secondly, thin film heating elements, such as thin filmcarbon fibers, are spread over a large area resulting in larger surfacearea for heat to be transferred. The surface area of thin film heatingelements can also be configured to enable heat transfer without creatingsubstantial disruption to the air flow as conventional coiled resistiveelements. Thirdly, since the little radiation that the thin film heatingelements do generate is in the far-infrared spectrum, the radiation isextremely well absorbed by the water vapor in the air that has a peak inabsorption wavelength at a similar wavelength as transmitted by the thinfilm heater elements. These three features combine to produce a heaterthat is ideally suited to heat air in a ducted system at higherefficiencies than filament type heaters. A secondary benefit from theradiation produced by thin film heating elements, such as thin filmcarbon fibers, is that such radiation further have beneficial antimicrobial effects as the far-infrared spectrum emitted results in theheating of water vapors in air-born microbes.

Various embodiments of the invention enable the heating of a desiredheated space using a forced warm-air room heating apparatus comprisingof an enclosure having an inlet to a supply of air, an outlet to thedesired heated space, and a series of panels constructed and arranged tocreate a series of air channels. A series of thin film heating elementsline the series of panels, which are generally arranged to increase theheat exchange characteristics of the thin film heating elements. Theseries of thin film heating elements generate warm, heated air in itsproximity by convection and radiative means. A fan assembly isoperatively coupled to the enclosure to force the warm heated air intothe desired heating space. In various alternative embodiments, the fanassembly can be mounted in proximity of the inlet, or in proximity tothe outlet, or in between the inlet and outlet within the enclosure. Itis further contemplated as an alternative embodiment that the fanassembly can be upstream or downstream to the enclosure and can bepushing or pulling the direction of air through the enclosure.

In an illustrative embodiment of the invention, the thin film heatingelements are thin film carbon fibers. An exemplary trade name for suchthin film heaters is a carbon thin-film. The thin film heaters can befurther sandwiched to provide protection from the environment. Anexample of a suitable material is fiberglass. The thin film heatingelements are electrically powered to generate heat when an electricpotential is applied across the film heating elements. The electricalcurrent can flow through the thin film heating elements or across thesurface of thin film heating elements depending on the characteristic ofthe electrical current. The electrical current applied can be DC or ACand the electrical potential applied can be constant or oscillating.

The thin film heating elements, such as thin-film carbon-heatingelements, efficiently heat up to a relatively moderate temperature, thusallowing the heat to convectively transfer to a medium in the channelwith minimal heat loss as radiation or conductive heat. Convection heattransfer is directly related to the surface area of the heating element,thus compressing the heater into a thin-film exposes relatively more airto a larger heating area, thereby increasing the heat transfer to theair. Additionally, thin film heaters emit smaller quantities ofradiation, thus less energy is emitted as waste. Additionally, theradiation emitted is generally short wavelength of the infrared (IR)spectrum close to the absorption wavelength of water, thus the thin filmheater enables efficient-absorption of energy by the water vapor presentin air, further improving the efficiency of the heating.

In various illustrative embodiments, the series of panels areconstructed and arranged to divide, deflect, or collectively divide anddeflect the airflow within the enclosure. It is further contemplatedwithin the illustrative embodiment that the series of panels can beconstructed and arranged in various configurations, including being asolid or a porous. The shape of the panels can be flat or curved, wherethe curvature is such to gently create gentle laminar flow across thesurface of the panels, or curved to aggressively create laminar flowacross the surface of the panels as air passes over. In variousalternative embodiments, the series of panels are constructed andarranged as air ducts. The air ducts can be shaped in configurationssuch that the cross section of the air duct can be in the shape of acircle, parabolic, square, rectangular, or other complex curve shapesthat allows air to flow through. In the various illustrativeembodiments, the thin film heating elements are constructed and arrangedas the plurality of panels to deflect, divide, or simultaneously deflectand divide air within the enclosure. It is contemplated in analternative embodiment that the thin film heating elements can align aportion of the surface of the panel, so long as the thin film heatingelements are within proximity of the air flow to allow the air flow tocarry the warm air generated by the thin film heating elements to theoutlet.

In an illustrative embodiment, the inlet and the outlet of the enclosureare opposed to one another. However, it is contemplated in alternativeembodiments that the inlet and outlet can be in any direction andorientation so long as the inlet has access to air supply and the outletis directed at the desired heating space.

In another illustrative embodiment, the forced warm-air room heater is awarm-air heating system comprising of the enclosure having the inlet,the outlet, the series of panels, and the series of thin film heatingelements. The system further comprises of sensors and controllersconfigured and arranged to measure temperature and flow and control thetemperature of the desired heated space. It is contemplated in variousillustrative embodiments that standard control, such asproportionate-integrator controller (PI), orproportionate-integrator-differentiator (PID) controller, are used. Invarious alternative embodiments, more advanced control techniques, whichshould be clear to those of skill in the art, can be employed, such asKarman filters, adaptive learning or training systems, or model basedcontrols.

In various alternate embodiments, the forced warm-air room heatingapparatus can be constructed and arranged in a series, in parallel, orin combinations of series and parallel with other forced warm-air roomheating apparatus. The forced warm-air room heating apparatus can bedirectly coupled to one another. In another alternate embodiment, it isfurther contemplated that components of the forced warm-air room heatingapparatus can be combined such that the air flow in a first forcedwarm-air room heating apparatus directly couples to air flow in a secondforced warm-air room heating apparatus. An illustrative example can bethe two or more warm-air heating apparatus operatively coupled to eachother in a series and operated by a single fan assembly configured andarranged to force air through the multiple enclosures.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a top cross-sectional view of the enclosure and the fanassembly according to an illustrative embodiment;

FIG. 2 shows a cross-sectional view of a panel assembly comprising of apanel and a thin film heating element;

FIG. 3 shows a top view of the plurality of thin film heating elementconfigured as a panel assembly;

FIG. 4 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of thin film heatingelements arranged along the walls of the enclosure according to analternative embodiment;

FIG. 5 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedin an alternating columns V-shaped prism according to an illustrativeembodiment;

FIG. 6 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedin an alternating columns of V-shaped prism according to an alternativeembodiment;

FIG. 7 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedin an alternating configuration of parallel horizontal fins according toan alternative embodiment;

FIG. 8 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedin an alternating configuration of parallel horizontal fins according toanother alternative embodiment;

FIG. 9 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedin alternating rows of V-shaped prism according to an alternativeembodiment;

FIG. 10 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedin alternating rows of V-shaped prism according to another alternativeembodiment;

FIG. 11 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedin an alternating configuration of parallel vertical fins according toan alternative embodiment;

FIG. 12 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedin an alternating configuration of parallel vertical fins according toanother alternative embodiment;

FIG. 13 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedto divide the air flow with a vertical column according to analternative embodiment;

FIG. 14 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedto divide the air flow with a horizontal column according to anotheralternative embodiment;

FIG. 15 shows a transparent perspective view of an assembly of theenclosure, the inlet, the outlet, and the plurality of panels arrangedto divide the air flow with an X-shape divider according to analternative embodiment;

FIG. 16 shows a top cross-sectional view of the forced warm-air heatingsystem comprising an enclosure, the fan assembly, and the controlleraccording to an illustrative embodiment;

FIG. 17 shows a flowchart of a method for controls of a forced warm-airroom heating system in accordance to an illustrative embodiment;

FIG. 18 shows a cross-sectional view of a building installed with aforced warm-air-room heating system in accordance to an illustrativeembodiment;

FIG. 19 shows a flowchart of an alternative method for controls of aforced warm-air room heating system in accordance to an illustrativeembodiment;

FIG. 20 shows a cross-sectional view of a building installed with analternative forced warm-air room heating system in accordance to anillustrative embodiment;

FIG. 21A shows an inlet view of an illustrative embodiment;

FIG. 21B shows an inlet view of an alternate embodiment;

FIG. 21C shows an inlet view of yet another alternate embodiment;

FIG. 21D shows an inlet view of yet another alternate embodiment;

FIG. 21E shows an inlet view of yet another alternate embodiment;

FIG. 21F shows an inlet view of yet another alternate embodiment;

FIG. 22A shows an outlet view of an illustrative embodiment;

FIG. 22B shows an outlet view of an alternate embodiment;

FIG. 22C shows an outlet view of yet another alternate embodiment;

FIG. 22D shows an outlet view of yet another alternate embodiment;

FIG. 22E shows an outlet view of yet another alternate embodiment;

FIG. 22F shows an outlet view of yet another alternate embodiment.

FIG. 23 shows an exposed side view with a side wall of the enclosureremoved to reveal the internal supporting structure of the enclosureaccording to an illustrative embodiment.

DETAILED DESCRIPTION

FIG. 1 shows a top cross-sectional view of an enclosure 102 and the fanassembly 103 according to an illustrative embodiment. The forcedwarm-air room heating apparatus 100 comprises an enclosure 102 havingthe fan assembly 103, an inlet 104, an outlet 106, a plurality of panels108, and a plurality of thin film heating elements 109. The plurality ofpanels 108 can be constructed of the plurality of thin film heatingelements 109 or the plurality of panels 108 can be constructed of aseparate material and the thin film heating elements 109 are mounted onthe plurality of panels 108.

In the illustrative embodiment, the plurality of panels 108 areconstructed and arranged to define a plurality of channels 110 andfurther arranged to increase the heat exchange characteristics bymaximizing exposed surface area 112 of the plurality of panel 108 to theplurality of channels 110. The heat exchange characteristics can befurther maximize by the formation of laminar flow 114 in air flow 116 asthe air flow 116 passes through the plurality of channels 110. Theplurality of panels 108 are constructed and arranged to divide anddeflect air flow 102. In another embodiment of the present disclosure,thin film heating element 109 can be constructed and arranged as theplurality of panels 108 to define the plurality of channels 110 andfurther arranged to increase the heating characteristic of the forcedwarm-air heating apparatus 100.

The air flow 116 is forced from fan assembly 103 through inlet 104 intoenclosure 102. As air flow 116 flows over the plurality of thin filmheating elements 109 air flow 116 is heated by convection to form heatedair flow 118. In an illustrative example, the apparatus 100 heats an airflow of 84 liters/second from 15.1 degree Celsius to 31.5 degree Celsiususing 2.4 kilowatt of power. This is an exemplary data and it should beclear that variations in performance can be observed due to thediffering components utilized and the differing arrangements of thecomponents.

In an illustrative embodiment, the apparatus 100 operates in a range of0.1 liters/second to over 108 liters/second. An illustrative example ofthe fan assembly 103 is a 200 liter AC centrifugal in-line fanmanufactured by Multifen GmGH, which produces a nominal airflow of 1200cubic meters per hour at 2,650 RPM. It is contemplated that other fanscapable of forcing an air flow is adequate, thus different fans ofdiffering volume and/or flow rates can be utilized. Other alternativeair forcing technology can be employed, such as axial fans, cross-flowfan, and other centrifugal fan.

It is contemplated in the illustrative embodiment that the plurality ofthin film heating elements 109 can be mounted on a single side or bothsides of the plurality of panels 108. The plurality of panels 109 or theplurality of thin film heating elements 109 are arranged such that asair flow 116 passes through the plurality of channels 110, thetemperature of heated air flow 118 increases incrementally, but notnecessarily, by the same increment across each panel. It is furthercontemplated in the illustrative embodiment that increasing the numberof thin film heating elements 109 arranged in series increases thetemperature of outlet air flow 120.

In various illustrative embodiments, the plurality of panels 108 or theplurality of thin film heating elements 109 directly couples to theenclosure 102. The plurality of panels 108 or plurality of heatingelements 109 is configured and arranged to provide structural supportfor the enclosure 102. In an alternative embodiment, the enclosure 102provides structural support to the plurality of panels 108 or theplurality of heating elements 109. In another alternative embodiment,the plurality of panels 108 or the plurality of thin film heatingelements 109 is supported by a plurality of support frames 122. Theplurality of support frames 122 is constructed of material having lowthermal conductive coefficient to minimize the waste from conductiveheating. Examples of material used to construct the support frame 122includes, but is not limited to, wood, ceramic, polymer, composite,and/or other thermally nonconductive materials. It is furthercontemplated that the structure of support frame 122 can be arranged asa solid or as a series of framework members to minimize conductive heattransfer from the plurality of thin film heating element 109 to theenclosure 102. Likewise any mounts between the wall of enclosure 102 andthe plurality of support frames 122 can include insulating connectors(not shown). In an illustrative embodiment, the enclosure 102 and thesupport frame 122 are manufactured of galvanized steel. However, invarious alternative embodiments, other material can be used to constructthe enclosure 102, or the support frame 122, including but are notlimited to, other heat resistant materials such as Steel, StainlessSteel, Zinkalume, Copper, Super Alloys, Intermetallics, Low AlloySteels, Carbon-carbon Composites, High Alloy Steels, Cast Iron, HighAlloy Cast Iron, Refractory Metals, Ferrous Alloys, Nickel Based Alloys,Cobalt Based Alloys, Zirconis, Ceramics, Titanium Based Alloys, and HighTemperature Resistant Polymers.

In various illustrative embodiments, the plurality of thin film heatingelements 109 is constructed substantially of thin film carbon fiber.Examples of thin film carbon fibers include, but is not limited to,graphite fiber, carbon graphite, turbostratic carbon fibers,polyacrylonitrile (PAN), rayon, and petroleum pitch.

In various illustrative embodiments, the thin film heating elements 109generate radiation 126, conductive heat 128, and convective heat 130 aselectrical power 132 is applied as shown in FIG. 2. The embodimentfurther shows one of the plurality of thin film heating elements 109mounted to one of the plurality of panels 108 by an insulating layer124. It is contemplated in the present disclosure that other means ofmounting can be employed. Further illustrated is an insulating layer134, which can thermally insulates panel 108 from thin film heatingelement 109, but also binds the panels 108 and heating elements 109together. Examples of other mounting can be using mechanical means, suchas screws, bolts, or nails, or alternatively using adhesives, such asglue, epoxy, or by attaching the thin film heating element 109 to thepanel 110 when the panel 110 is melted.

Heat from the plurality of thin film heating elements 109 is transferredthrough three different mechanisms that will be apparent to thoseskilled in the art: conduction, convection and radiation. Conduction ischaracteristic of heat transfer between two mediums of similar densityand phase. Convection is the transfer of heat between two materials ofdifferent density and phase. For convection to occur, a transfer mediummust be able to flow over the heated medium either naturally or byforce. When heat is allowed to flow naturally, that is called naturalconvection. When heat is forced by, for example, a fan or impeller, thatis defined as forced convection. Radiation, conversely, is heat-transferby photons, where the medium that the photons travel though is notsubstantially heated, but the object that absorbs the radiation on theother end of the medium does absorb it. Air is generally heated byconvection since radiation passes mostly though it and conduction heattransfer between two fluids is considered convection since the fluidsmove and mix at their interface.

As contemplated in various illustrative embodiments, convection directlyrelates to the surface area of the heating element, thus compressing theheater into a thin-film exposes relatively more heat transfer medium,such as air or water, to a larger heating area, thereby increasing theheat transfer to the air. By ways of example, a thickness of 0.6 mm to1.0 mm is sufficiently suitable to generate the moderate heating;however, thinner films can be employed. Moderate temperature increasesat the surface of the plurality of thin film heating elements can befrom a range of 1 degree Celsius to 80 degree Celsius.

It is contemplated in the various illustrative embodiments thatconductive heat 128 is considered wasted heat since the energy expend ingenerating conductive heat 128 does not result in heating the desiredspace. Thus, various alternate embodiments employ a variety ofmechanisms to minimize conductive heat 128. In an alternativeembodiment, the plurality of thin film heating elements 109 are directlymounted to enclosure 102, thus the contact between the plurality of thinfilm heating elements 109 and enclosure 102 is minimized. In anotheralternate embodiment, thermal insulating buffers can be installedbetween the plurality of thin film heating elements 109 and enclosure102 to further minimize conductive heat 128. Example of such thermalinsulating buffer may be plastic or ceramic washer, bolts, or any typeof thermal insulating material that can be use in mounting. In yetanother alternate embodiment, the outer surface of enclosure 102 isequipped with fins or heat dissipating structure exposed to the desiredheating space, thus employing the conductive heat 128 to assist theheating of the desired heating space.

It is contemplated in the various illustrative embodiments that theplurality of thin film heating elements 109 emit smaller quantities ofradiation 126, which is closer to the absorption wavelength of water. Asa result, firstly, less energy is emitted as waste. Secondly, of thelittle radiation that is emitted, much is thus absorbed by vapor in theair, which is commonly characterized as humidity, thus improving theefficiency of the heating of the heated air 134. Strong absorbance bywater vapor generally occurs at wavelengths of 2500, 1950, and 1450nanometers (nm). The radiation emitted from thin film heating elements,such as thin film carbon fibers, substantially overlaps with the strongabsorbance wavelength of water vapor. It is further contemplated in analternative embodiment that humidity within the enclosure 102 can becontrolled to provide the optimal water vapor absorption of theradiation emitted by the thin film heating elements.

In FIG. 3, a top view of one of the plurality of thin film heatingelements 109 is shown mounted in a panel assembly 136. In thisillustrative embodiment, the panel assembly 136 is shown comprising of aplurality of thin film heating elements 138, two conductors 140 and 142,a panel frame 144, and protective layers 146. As an illustrativeexample, the thin film heating elements 138 are sandwiched by two 0.5 mmfiberglass protective layers 146, which are 450 mm by 450 mm to form thepanel assembly 136. Encased inside the sandwich construction, four thinfilm heating elements 138 are connected to the superior copperconductors 140 and one inferior copper conductor 142. The two superiorcopper conductors 140 and 142 are respectively connected to phase andneutral. The carbon panels are induced with electricity that travelsthrough the thin film heating elements 138, which acts as a resistor andheats up as electric current flows through it. In an example of theillustrative embodiment, a voltage potential of 220-240 VAC is appliedacross each of the plurality of thin film heating elements 109. Itshould be clear to those skilled in the arts that voltage potential canvariedly accordingly to operate with other voltage potential. In anexample of (24) thin film heating elements 109 configured in a parallelconfiguration consuming 2.4 KW results in a 16.1 degree Celsius increasein the temperature between the inlet 104 and the outlet 120 at an airflow rate of 108 liters/second.

Various alternative embodiments of the invention are shown in FIGS.4-15, which show various arrangements of the plurality of panels 108 andthe plurality of thin film heating elements 109 in the enclosure 102. InFIG. 4, an alternate embodiment is shown, wherein the plurality of thinfilm heating elements 109 line the walls of the enclosure 102. It shouldbe clear that the inlet 102 and outlet 120 are shown to provideorientation as other components contemplated in the alternate embodimentare omitted to simplify the drawings.

In FIG. 5 and FIG. 6, alternate embodiments are shown, wherein theplurality of thin film heating element 109 and the plurality of panels108 are arranged as alternating columns of triangularly shaped prism.FIG. 5 illustrates an illustrative configuration of this arrangement andFIG. 6 illustrates a configuration mirroring the configuration of FIG.5.

In FIG. 7 and FIG. 8, alternate embodiments are shown, wherein theplurality of thin film heating elements 109 and the plurality of panels108 are arranged as alternating columns of vertical walls. FIG. 7illustrates an illustrative configuration of this arrangement and FIG. 8illustrates a configuration mirroring the configuration of FIG. 7.

In FIG. 9 and FIG. 10, alternate embodiments are shown, wherein theplurality of thin film heating elements 109 and the plurality of panels108 are arranged as alternating rows of triangularly shaped prism. FIG.9 illustrates an illustrative configuration of this arrangement and FIG.10 illustrates a configuration mirroring the configuration of FIG. 9. InFIG. 9, the air flow 118 is directed upward first, thus resulting in adiffering air flow path to the air flow configuration shown in FIG. 10.

In FIG. 11 and FIG. 12, alternate embodiments are shown, wherein theplurality of thin film heating elements 109 and the plurality of panels108 are arranged as alternating rows of horizontal walls. FIG. 11illustrates an illustrative configuration of this arrangement and FIG.12 illustrates a configuration mirroring the configuration of FIG. 11.

The difference in the air flow path between mirroring configurations ofthe plurality of thin film heating elements 109 and the plurality ofpanels 108 is demonstrated in FIG. 13 and FIG. 14. In FIG. 13, thealternate embodiment a vertical divider represents a plurality of panels108 and the plurality of thin film heating elements 109 that separatethe air flow 118 to a left side and a right side of the enclosure 102.Alternatively, in FIG. 14, the alternate embodiment comprises ahorizontal divider representing the plurality of panels 108 and theplurality of thin film heating elements 109. Since heat has a tendencyto rise, the heating pattern in the upper channel as compared to thelower channel differs.

In FIG. 15, an alternate embodiment is shown, wherein the plurality ofthin film heating elements 109 and the plurality of panels 108 arearranged as a horizontal X-shape structure. In another alternateembodiment of FIG. 15, the plurality of thin film heating elements 109and the plurality of panels 108 are arranged to form a honeycomb shapedstructures between the inlet and the outlet of the enclosure 102 (notshown). The honeycomb structure can be configured to have across-sectional hexagonal shape, a cross-sectional square shape, across-sectional rectangular shape, or a cross-sectional rhomboid shape.

FIG. 16 shows an illustrative embodiment of the warm-air room heatingsystem comprising of the apparatus 100 and a plurality of temperaturesensor 152 and a plurality of flow rate sensor 154 operatively coupledwith a controller 150. A temperature reading is communicated from thetemperature sensor 152 to the controller 150 via a temperature controlline 154. It should be clear to those skilled in the arts thattemperature control line 154 can contain several voltage line and/orseveral signal commands and data. The communication can be binary oranalog. An example of signal levels employed by the system includes acurrent signal varying between 4-20 mA where 4 mA represents the minimumtemperature read of the system and 20 mA represents the maximumtemperature read of the system. It should be clear to those skilled inthe arts that the controller 150 operatively couples with the fanassembly 118 and the plurality of thin film heating elements 109 toregulate the air flow through the enclosure 102 and the heatinggenerated by the apparatus 100 respectively. The controller 150 canemploy various methods of controls, for example, such as proportionateintegrator (PI) control, proportionate integrator differential (PID)control to regulate the temperature in the desired heating space. It isfurther contemplated in the illustrative embodiment that the controller150 can further control the humidity level of the desired heating spaceby controlling an auxiliary system (not shown) that can introducemoisture into the path of air flow 118.

In various alternate embodiments, as further shown in FIG. 16, thesystem can be configured with a plurality of safety devices, such as anover-temperature probe, and a minimum-flow-rate probe. Each of theplurality of safety devices is serially connected to the controllerengaged switch, thus an out-of-bound condition in any of the pluralityof safety devices results in a break in the electric supply to theplurality of thin film heating elements 109.

An example of the over-temperature probe in the alternate embodimentconsists of a maximum temperature threshold circuit configured togenerate an output signal when the sensed temperature in the enclosure102 exceeds a predetermined threshold. An example of such apre-determined threshold is 95 degree Celsius. As an example of thealternate embodiment, a normally-closed switch coupled to a thermistoris employed as an over-temperature probe. Multiples over-temperaturesensing is desirable since different section of the enclosure 102 heatsup at different rate.

An example of the minimum-flow-rate probe consists of a minimum flowrate threshold circuit configured to generate an output signal when thesensed flow rate is below a pre-determined threshold. An example of sucha pre-determined threshold is 10 liters/second. As an example of thealternate embodiment, a normally-open switch coupled with a flow-meteris employed as a minimum-flow-rate probe. A single flow-rate sensor isdesirable since the flow-rate results in a disturbance of the flow path.Additionally, air flow is the same when differential pressure across theenclosure 102 is the nearly zero. In various illustrative embodiments,the fan assembly 103, the plurality of panels 108, and the plurality ofthin film heating elements 109 are configured and arranged to minimizedthe differential pressure across the enclosure 102 since differentialpressure results when there is an significant obstruction to the flow ofair and such obstruction would hinder the transferability of the heatair to the desired heating space. It should be clear to those skills inthe arts that various techniques exist and can be employed to measuretemperature or flow rate.

Additionally, it should be further clear to those skilled in the artsthat various control schemes for such safety devices exist and can beemployed to protect against over temperature events and under-flowevents.

In an alternate embodiment, the plurality of temperature sensors 152 andthe flow sensor 158 can be binarized and used within a logic controlcircuit. FIG. 17 shows an example of the logic control circuit 160 thatoperates on binarized sensed signal from the plurality of temperaturesensor 152 and the flow rate sensor 158. Reading from temperature sensor162 is fed into maximum-temperature detector 166. Themaximum-temperature is a binarized threshold detector. If themaximum-temperature detector 166 does not detect an over-temperaturereading, the logic circuit 160 goes to a null waiting state in state172. However, if the maximum-temperature detector 166 detects anover-temperature reading in one of the plurality of heating elements109, the logic circuit 160 goes to emergency heating break state 174. Inthe emergency heating break state 174, the power to the plurality ofthin film heating elements 109 is cut. The logic circuit 160 wouldreturn to state 162 once the error is cleared by the operation, orsufficient time has passed for the temperature reading of the pluralityof heating elements 109 to drop below the trip threshold. In analternate embodiment, additional signal processing can be employed withthe threshold detector, such as a hysteresis circuit, or a low-passfilters to minimize the likelihood of false-trips in theover-temperature detector 166.

Reading from the flow-rate sensor 158 is captured in step 164. Thereadings are fed to a minimum flow-rate detector 168. If the minimumflow-rate is above the minimum flow-rate threshold, the logic circuit160 goes to the null waiting state in state 172. However, if the minimumflow-rate detector 164 detects an under flow rate reading, the minimumflow-rate detector 168 signals the logic circuit 160 to check theheating elements activated state 170. If the plurality of thin filmheating elements is not energized, the logic circuit 160 does nothingand waits in the null waiting state 172. However, if the thin filmheating elements are energized, the logic circuit 160 is directed toenter emergency heating break state 174, thus disabling the thin filmheating elements 109. The logic circuit 160 can exit the break state 174through the various mechanisms discussed above. It is furthercontemplated that the various embodiments of the illustrative embodimentand the alternative embodiment can operate with out an over-temperaturesensor or a minimum-flow-rate sensor.

It is contemplated in this illustrative embodiment that the inputs ofthe plurality temperature sensor 152 and the flow-rate sensor 158 arecontinuously monitored by the controller 150. Examples of the placementof the plurality of temperature sensor includes the first thin filmheating element of the plurality of thin film heating elements 109 inproximity to the inlet 104, the last thin film heating element of theplurality of thin film heating elements 109 in proximity to the outlet120, and the thin film heating element of the plurality of thin filmheating elements 109 centrally located in the enclosure 102. It iscontemplated in the present embodiment and should be clear to thoseskilled in the arts that output from the plurality of temperaturesensors are fed to a plurality of over-temperature detector 166 and anover temperature event results in a tripping state with the logiccircuit 160 directed to emergency heating break state 174.

It is further contemplated in the various illustrative embodiments thatthe electric cables used in the safety and control circuits are ratedabove 180 degrees Celsius and further are coated in fiberglass forsafety.

FIG. 18 shows an alternate embodiment of the control logic 160 for thesystem depicted in FIG. 17. While the temperature in room 210 is abovethe set temperature of thermostat 212, the logic does nothing However,as soon as temperature sensor 222 reads below the set point of thethermostat, the fan assembly 218 and then soon after forced warm-airheating apparatus 100 is energized so that air will flow though ductedsystem 206. As the air flows though forced warm-air heating apparatus100, it is heated as the plurality of thin film heating elements 109heat up. This transforms the cool air entering inlet duct 220 into hotair exiting spigot 216 with net effect of increasing the temperature inroom 210. When thermostat 212 senses the air temperature in room 210 tobe above the thermostat set point, the forced warm-air heating apparatus100 and then the fan assembly 218 turns off. The above description is byno means the only way to incorporate the forced warm-air heatingapparatus 100, the fan assembly 218 and a ducted air system to heat air.The multitude of combinations of push and pull fans, with the ability toutilize valves and multiple duct work is endless as will be evident tothose skilled in the art.

A possible control scheme for the configuration of FIG. 17 is shown inFIG. 18. Control system 204 continuously monitors room 210's temperaturethough thermostat 212, as soon as the temperature in room 210 dropsbelow the thermostat set point, controller 204 switches the fan assembly218 on. At this point controller 204 reads cavity 202 temperature withtemperature sensor 222. If the cavity 202 temperature is above the setpoint, the system will do nothing and hot air will flow from roof cavity202 into room 210. However, if the roof cavity 210 temperature is belowthe set point temperature, controller 204 will engage the forcedwarm-air heating apparatus 100, turn the plurality of thin film heatingelements 109 on and allow the air flowing from roof cavity 202 to beheated before it is releases into room 210.

As an example of the various illustrative embodiments, forced warm-airroom heating apparatus 100 is shown installed as part of an internalducting system of a house 200 in FIG. 19. House 200 consists of room 210and roof cavity 202. The ducted system 206 of house 200 is a series ofcomponents, starting with inlet duct 208, through apparatus 100 past thefan assembly 218 though an outlet spout 216. Room 210 is equipped withthermostat 212, which includes a temperature setting device and athermometer. Thermostat 212 is connected to controller 204 viacommunications link 214. It is further contemplated in the presentembodiment that the forced warm-air heating apparatus 100 is furtherequipped with a communication module that enables a user to remotelycontrol the forced warm-air heating apparatus 100 to set the temperatureset-point in the desired heating space.

In an illustrative embodiment, the communication module enables one way,or two way communication between the controller 150, which isoperatively coupled to the forced warm-air heating device 100, and tothe thermostat. It should be clear to those skills in the arts thatother user friendly setting and operating set-points can be communicatedover the remotely control communicate. It is further contemplated thatthe communication module can be operated over a wireless communication.Examples of wireless communication system includes, but not limited to,various 900 MHz and 2.4 GHz spectrum wireless system, such as Ethernet802.11a/g/n, Bluetooth, and Zigbee. Other consumer communicationprotocols can also be utilized, such as an X-10, and other wirelesscommunication such as infrared, and low power radio.

In an alternate embodiment, FIG. 20 shows another configuration of aductwork 220 for the forced warm-air heating apparatus 100. The ductwork220 is exposed to air supply in the roof cavity 202. This configurationenables the room 210 to be heated by the air in roof cavity 202 as longas there is a positive temperature difference between roof cavity 202and room 210. The present heating embodiment is achieved by operatingthe fan assembly 218 and forcing the hot air from the roof cavity 202into the room 210. However, when the temperature in the room cavity 202is lower than the temperature in the room 210 as sensed by temperaturesensor 222 in the room cavity 202, the forced warm-air heating apparatus100 collectively energizes the plurality of thin film heating elements109 and the fan assembly 218 to heat air from the roof cavity 202sufficiently heat the room 210.

In an example of the illustrative embodiment as shown in FIG. 19 andFIG. 20, the inlet duct size 208, 220 is 200 mm in diameter. In variousalternate embodiments, the diameter size of the inlet duct can bebetween 10 mm and 1000 mm. In an illustrative embodiment, the outletduct size 216 is 300 mm in diameter. In various alternate embodiments,the outlet duct size 216 can be between 10 mm and 1000 mm. It should beclear to those skilled in the arts that the various diameter sizes canvary for the appropriate heating application.

In various illustrative embodiments, the various configurations of theinlet 104 is shown in FIG. 21A-FIG. 21F. It should be clear to thoseskilled in the arts that the location, size, and number of the inlet 104can be varied to compel the air flow into the enclosure 102 to generatelaminar flow along the surface of the plurality of thin film heatingelements 109, while minimizing the formation of turbulent flowthroughout the plurality of channels 110 in the enclosure 102. Thus, theinlet 104 can be arranged, sized, numbered in such a way as to affectthe airflow characteristic with respect to the plurality of thin filmheating elements 109. For example, in FIG. 21B and FIG. 21C, a pluralityof inlets 104 is employed to generate an impingement in the air flow asthe air flow is flows across the first of the plurality of thin filmheating element 109 in the enclosure 102. Various shapes can be employedto generate the same effects as shown in FIG. 21D, where a square shapedinlet 104 is employed. The impingement effects can be further altered bymultiple square inlet 104 as shown in FIG. 3E and FIG. 3F.

In an illustrative embodiment, FIG. 23 shows an exposed side view with aside wall of the enclosure 102 removed to reveal the internal supportingstructure of the enclosure 102 according to an illustrative embodiment.The plurality of panels 108 is shown as an downward X-shape truss 232 toreveal the supporting interior structure of the enclosure 102. Acomplementary upward X-shape truss 230 is also shown. The presentembodiment provides an example of the plurality of thin film heatingelements 109 providing internal support to the enclosure 102.

The foregoing has been a detailed description of illustrativeembodiments of the invention. Likewise, the drawings presented hereinshould be considered as only illustrative of particular examples of theinvention. Various modifications and additions can be made withoutdeparting from the spirit and scope of this invention. Each of thevarious embodiments described above may be combined with other describedembodiments in order to provide multiple features. Furthermore, whilethe foregoing describes a number of separate embodiments of theapparatus and method of the present invention, what has been describedherein is merely illustrative of the application of the principles ofthe present invention. For example, while the heating has been shown ina home context, it can be used in various other settings, such as avehicle setting, a temporary structure, such as a tent, an office andindustrial type buildings. The control mechanism employed, are likelyvariable,

In addition, the heater can be coupled to other in-line heating systemto operatively enhance the function of or to supplemental otherancillary functions such as, but not limited to, a cooling system, ahumidifier system, a dehumidifier system, air filtration system, an airpurification system, and other air conditioning system. Moreover, thesystem can be packaged in a portable system or a permanent fixed basedsystem. Accordingly, this description is meant to be taken only by wayof example, and not to otherwise limit the scope of this invention.

What is claimed is:
 1. A forced warm-air room heating apparatuscomprising: an enclosure having an inlet, an outlet, and a plurality ofpanels, wherein the plurality of panels are constructed and arranged todefine a plurality of channels that increases heat exchangecharacteristics as air passes thereover; a plurality of thin filmheating elements lining some of the plurality of panels constructed andarranged to produce warm heated air in each of the plurality ofchannels; and a fan operatively coupled to the enclosure to force thewarm heated air through each of the plurality of channels to the room.2. The forced warm-air room heating apparatus of claim 1 wherein some ofthe plurality of panels are constructed and arranged to at least one ofdividing and deflect the direction of flow from the inlet to the outletthrough the plurality of channels.
 3. The forced warm-air room heatingapparatus of claim 1 wherein some of the plurality panels areconstructed and arranged as a planar surface, a curve surface to gentlygenerate laminar flow, and a curve surface to aggressively generatelaminar flow.
 4. The forced warm-air room heating apparatus of claim 1wherein the plurality of thin film heating elements is constructed ofthin film carbon fibers substantially comprised of carbon.
 5. The forcedwarm-air room heating apparatus of claim 1 wherein the plurality of thinfilm heating elements is electrically powered.
 6. The forced warm-airroom heating apparatus of claim 1 wherein the plurality of panels isconstructed and arranged as a plurality of air ducts.
 7. The forcedwarm-air room heating apparatus of claim 1 wherein some of the panels ofthe plurality of thin film heating elements align a substantial portionof a panel of the plurality of panels.
 8. The forced warm-air roomheating apparatus of claim 1 further comprising a thermal insulatinglayer between the plurality of heating elements and the plurality ofpanels.
 9. The forced warm-air room heating apparatus of claim 8 whereinthe thermal insulating layer comprises at least one of galvanized steel,steel, stainless steel, zinkalume, copper, super alloys, intermetallics,low alloy steels, carbon-carbon composites, high alloy steels, castiron, high alloy cast iron, refractory metals, ferrous alloys, nickelbased alloys, cobalt based alloys, zirconis, ceramics, titanium basedalloys, and high temperature resistance polymers.
 10. A forced warm-airroom heating system comprising: an enclosure having a fan assembly, aninlet, an outlet, a plurality of panels, and a plurality of thin filmheating elements, wherein the plurality of panels is constructed andarranged to define a plurality of channels that increases heat exchangecharacteristics as air passes thereover, wherein the plurality of thinfilm heating elements line some of the plurality of panels constructedand arranged to produce warm heated air in each of the plurality ofchannels, and wherein the fan assembly is configured and arranged tooperatively couple to the enclosure to force the warm heated air througheach of the plurality of channel; and a controller assembly comprising aplurality of sensors and a processor, wherein the plurality of sensorsare arranged within the room to measure thermal properties within room,and wherein the processor operatively couples to the sensor to controlat least one of the energizing of at least some of the plurality of thethin film heating elements and the fan assembly.
 11. The forced warm-airroom heating system of claim 10 wherein the plurality of thin filmheating elements is constructed of thin film carbon fibers substantiallycomprised of carbon.
 12. The forced warm-air room heating system ofclaim 10 wherein some of the plurality of panels are constructed andarranged to at least one of divide and deflect the direction of flowfrom the inlet to the outlet through each of the plurality of channels.13. The forced warm-air room heating system of claim 10 wherein some ofthe plurality panels are constructed and arranged as a planar surface, acurve surface to gently generate laminar flow, and a curve surface toaggressively generate laminar flow.
 14. The forced warm-air room heatingsystem of claim 10 wherein the plurality of panels is configured as aplurality of air channel comprises a plurality of air ducts.
 15. Theforced warm-air room heating system of claim 10 wherein some of thepanels of the plurality of thin film heating elements align asubstantial portion of a panel of the plurality of panels.
 16. Theforced warm-air room heating system of claim 10 wherein the plurality ofsensor further comprises a flow sensor, wherein the flow sensor measuresa rate of air flow data within at least one of the plurality ofchannels, and wherein the controller further operatively coupled to theflow sensor to receive the rate of air flow data.
 17. The forcedwarm-air room heating system of claim 10 wherein the controller furthercomprises a communication module configured to receive a desiredtemperature set-point from a user interface.
 18. The forced warm-airroom heating system of claim 17 wherein the communication module isconfigured to receive the desired temperature set-point from the user byelectromagnetic waves.
 19. A method of heating a desired heating spaceusing warm air comprising: energizing a plurality of the thin filmheating elements arranged to a plurality of channels to generate a warmair mass in the plurality of channels; forcing an air flow by a fanassembly to at least one of deflect and divide the air flow to compelthe warm air mass from at least some of the plurality of channels to thedesired heating space.
 20. The method of claim 19 wherein some of theplurality channels is constructed and arranged with a plurality of curvesurfaces to at least one of gently generating laminar flow andaggressively generating laminar flow as the air flow passes over thesurface of at least one of the plurality of thin film heating elements.